How to Best Protect Your Garden and Plants During Heat Waves

The summers of Northern Sacramento Valley in California are warm and sweet, but the recent global warming causes the heat waves to become almost unbearable especially to crops and plants. Plants are 85% to 90% water, so they get dehydrated more quickly than people do during hot days. As a result, Northern California gardeners take steps further to protect their garden plants from wilting to death.

Maintaining a garden during the summer is more challenging for those practicing organic gardening. This is because they don’t just use any type of gardening products available. They need to ensure that everything they use on their plants is natural and chemical-free. When choosing organic gardening supplies including topsoil, landscape soil blends, soil amendments and landscape mulch, it’s best to research the different brands and get insights from other organic gardeners. The use of these supplies in caring for your garden during the summer must also be carefully carried out because the careless use of some products may cause more damage during heat waves.

To safely maintain an organic summer garden, here are the things you must do to protect your crops and plants from extreme heat.

Water Adequately in the Morning and Early Evening

Your garden plants are best watered in the morning and evening during summer. This is because the temperature during these times is more conducive for water absorption. The morning water will equip your plants with adequate moisture to withstand the day’s heat, and the evening water will help your plants replenish the moisture they lost during the exposure.

If you try to water around noon, when the sun’s heat is at its peak, the water will just evaporate even before the soil can absorb it. Also, it can be dangerous for your plants if you are using an exposed hose or if the water comes from an exposed pipe because the heat in the environment can cause the water in the pipes to heat up. So if you sprinkle the heated water over your plants, it can scald the leaves and damage their natural protective properties.

More importantly, a noontime watering can also be dangerous to the gardener because the exposure to extreme heat can cause health problems like heat exhaustion, heat stroke, sun burns, and dehydration.

The most effective and cost-effective method of watering is hand watering, that is, using a watering can or watering hose because you can control the amount of water that goes to your plants. Using a sprinkler may work if you have a larger space, but it can only water the targeted crops and some of the water from it are lost to evaporation in the heat and wind, so your plants may end up being under-watered. A soaker, on the other hand, is good for irrigating a vegetable garden, but because you usually can’t see how much water is delivered to the soil, your plants may end up being over-watered.

Under-watering and over-watering are both risky for your plants. If the crops go under-watered for days, they can wilt and eventually die from dehydration. If the crop is continually over-watered, the roots may “suffocate” and rot, and fungal diseases may develop and spread throughout your garden.

Use Mulch Around Your Plants

The use of mulch does not only help ward off weeds, it also helps to keep the soil moist and cool for your plants. You can use pretty much any type of mulch because they work almost just the same. However, during summer, it is best to use light-colored mulch because they tend to “reflect” the light of the sun from the ground; thus decreasing the rate of evaporation of water so the soil can retain more moisture. Examples of light-colored mulch are grass clippings, straw, and even chopped leaves. Check out our Cedar-Shred Bark Mulch!

Grass clippings and chopped leaves are the easiest to obtain. Just fit a grass catcher to your mower to chop the leaves and grass, then allow the clippings to dry out on your lawn for a few days before using as mulch.

Straw is more preferable for vegetable gardens. However, store-bought straw may contain viable grain seeds, so make sure that you ask only for the clean straw. When used as mulch, straw must be applied quite thickly to ensure that it doesn’t let the heat through to the soil. Also, keep in mind that hay is different from straw; hay will always have seeds that can cause your soil to grow unwanted plants.

Whatever mulch you decide to use for your summer garden, make sure to apply it on top of the soil, not mix it with the soil. Mulch works great simply as a covering to prevent the sun and the warm gusts of wind from drying up the soil around your plants.

Use Shading for Your Heat-Sensitive Plants

If you are growing cool-weather crops in your vegetable garden, it’s best to use shade netting over them to help filter the heat and prevent them from getting sun burnt. A shade cover benefits your crops in two ways: first, the shade keeps the covered soil cooler than the exposed soil so the plants can continue to grow; second, the shade protects the plants from the scorching sunlight so they can still produce a fresh, crisp harvest. The same applies to your cool-weather flowers; with proper shading, your flowers can continue to grow so they can bloom at the right season.

Below is a listing of vegetables and flowers that are heat-sensitive:

Vegetables

Broccoli

Spinach

Kohlrabi

Cilantro

Chinese cabbage

Brussels sprouts

Kale

Carrots

Radishes

Swiss chard

Cauliflower

Arugula

Lettuce

Peas

Most salad greens

Flowers

Pansies (annual)

Sweet peas (annual)

Oriental poppies (perennial)

Bleeding heart (perennial)

Snap dragons (annual)

Petunias (annual)

Though most plants can suffer from dehydration due to extremely hot temperatures, there are plants that thrive best in full sun. These plants are better exposed under the sun, because they need the heat to produce their crops or flowers. However, this doesn’t mean that these plants need less watering. In fact, sun-loving plants will need more water than other plants so they stay hydrated throughout their exposure.

Below is a listing of crops and flowers that thrive in the sun:

Vegetables/Fruits

Tomatoes

Melons

Eggplants

Peppers

Squash

Corn

Beans

Cucumbers

Watermelon

Flowers

Gazania (annual)

Portulaca (annual)

Zinnias (annual)

Gaillardia (annual)

Asters (perennial)

Day lilies (perennial)

Snow-in-summer (perennial)

Shasta daisies (perennial)

Lavender (perennial)

Lamb’s ear (perennial)

Sun-loving plants may enjoy the exposure but if you think that a heat wave is too much even for your sun-lovers, you may cover them with a shade netting during the hottest hours of the day and remove the shade when the heat becomes more tolerable.

A shade netting is the most ideal material to use for plants because it can withstand wind so it won’t fall on the plants and harm them. Shade cloths can also be used, but it must be applied with great care as it might fall on the plants and suffocate them when it gets too windy. When using a shade cloth, it is better placed above the plants or on one side only, where the heat penetrates directly.

Keep Your Grass Taller Than Usual

Regular mowing keeps your lawn looking sharp and manicured, but you can skip it during the summer to allow your grass to grow taller. Your grass can provide some shade for the soil and some low-growing plants. They can also help retain moisture in the soil by protecting it from hot gusts of wind and direct sunlight. You can still mow in the summer if the grass grows too tall for your taste, but it’ll be healthy for your summer garden to grow them up to three to six inches tall.

Place New Transplants Near Taller Plants

Ideally, you should avoid setting out transplants during summer when heat waves are common. The summer is a hard season for new transplants because their roots are still shallow and the hot temperature can quickly dry the soil’s top few inches. However, if you really need to set out some transplants during the hot season, it will be better for them to be placed near taller plants. The tall plants can provide them shade and at the same time allow them to be cast with enough sunlight so they can grow healthy despite the heat.

Put the Fertilizers on Hold

Although organic fertilizers won’t do harm to your crops and grass when applied during summer season, it may be ineffective because the stress from the hot temperature can weaken the plants’ ability to absorb nutrients from fertilizers. So even if you apply a generous amount of fertilizers, your plants may remain stunted and grow slowly throughout the season. This will only result to waste of good fertilizers and waste of money.

Maintain Your Gardening Tools

Besides taking extra care of your plants during heat waves in the summer, you should also take care of the equipments you use for tending the garden. Your tools’ condition can directly affect the health of your plants. For example, if you are using a plastic hose for your sprinkler or soaker, you should always check its material integrity before and after each use because constant heat exposure can cause plastic materials to crack or disintegrate. Cracks in your watering hose will cause leaks, and if the leaks go unnoticed during watering, your plants will be under-watered and become dehydrated throughout the day’s exposure.